| Records |
| Author |
Steven Franke, Daniela Jansen, Sebastian Beyer, Niklas Neckel, Tobias Binder, John Paden, Olaf Eisen |
| Title |
Complex Basal Conditions and Their Influence on Ice Flow at the Onset of the Northeast Greenland Ice Stream |
Type |
Journal |
| Year |
2021 |
Publication |
Journal of Geophysical Research: Earth Surface |
Abbreviated Journal |
|
| Volume |
126 |
Issue |
3 |
Pages |
e2020JF005689 |
| Keywords |
basal roughness bed conditions Greenland Ice Sheet ice stream Northeast Greenland Ice Stream radio-echo sounding |
| Abstract |
Abstract The ice stream geometry and large ice surface velocities at the onset region of the Northeast Greenland Ice Stream (NEGIS) are not yet well reproduced by ice sheet models. The quantification of basal sliding and a parametrization of basal conditions remains a major gap. In this study, we assess the basal conditions of the onset region of the NEGIS in a systematic analysis of airborne ultra-wideband radar data. We evaluate basal roughness and basal return echoes in the context of the current ice stream geometry and ice surface velocity. We observe a change from a smooth to a rougher bed where the ice stream widens, and a distinct roughness anisotropy, indicating a preferred orientation of subglacial structures. In the upstream region, the excess ice mass flux through the shear margins is evacuated by ice flow acceleration and along-flow stretching of the ice. At the downstream part, the generally rougher bed topography correlates with a decrease in flow acceleration and lateral variations in ice surface velocity. Together with basal water routing pathways, this hints to two different zones in this part of the NEGIS: the upstream region collecting water, with a reduced basal traction, and downstream, where the ice stream is slowing down and is widening on a rougher bed, with a distribution of basal water toward the shear margins. Our findings support the hypothesis that the NEGIS is strongly interconnected to the subglacial water system in its onset region, but also to the subglacial substrate and morphology. |
| Programme |
1180 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2169-9003 |
ISBN  |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7272 |
| Permanent link to this record |
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| |
| Author |
Charlène Guillaumot |
| Title |
Modelling the response of Antarctic marine species to environmental changes. Methods, applications and limitations. /// Modéliser la réponse des espèces marines antarctiques aux changements environnementaux. Méthodes, applications et limites. |
Type |
Thesis |
| Year |
2021 |
Publication |
Thèse de doctorat. université libre de bruxelles / université de bourgogne franche-comté |
Abbreviated Journal |
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| Volume |
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Issue |
|
Pages |
620 pp. |
| Keywords |
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| Abstract |
Parmi les outils qui permettent de mieux comprendre les systèmes naturels, la modélisation écologique a connu un essor particulièrement important depuis une vingtaine d’années. Les modèles écologiques, représentation simplifiée d’une réalité complexe, permettent de mettre en avant les facteurs environnementaux qui déterminent la niche écologique des espèces et de mieux comprendre leur réponse aux changements de l’environnement. Dans le cas des faunes marines antarctiques, la modélisation écologique fait face à plusieurs défis méthodologiques. Les jeux de données de présence des espèces sont très souvent agrégés dans le temps et dans l’espace, à proximité des stations de recherche. Ces données sont souvent trop peu nombreuses pour caractériser l’espace environnemental occupé par les espèces ainsi que leur physiologie. Enfin, les jeux de données environnementales manquent encore de précision pour finement représenter la complexité des habitats marins. Dans ces conditions, est-il possible de générer des modèles performants et justes à l’échelle de l’océan Austral ? Quelles sont les approches possibles et leurs limites ? Comment améliorer les méthodes afin de générer de meilleurs modèles ? Au cours de ce travail de thèse, trois types de modèles ont été étudiés et leurs performances évaluées. (1) Les modèles physiologiques de type DEB (Dynamic Energy Budget) simulent la manière dont l’environnement abiotique influe sur le métabolisme des individus et proposent une représentation de la niche fondamentale des espèces. (2) Les modèles de distribution d’espèces (SDMs pour Species Distribution Models) prédisent la probabilité de distribution des espèces en étudiant la relation spatiale entre données de présence et environnement. Ils proposent une représentation de la niche réalisée des espèces. Enfin (3), les modèles de dispersion de type lagrangien prédisent le mouvement de propagules dans les masses d’eau. Les résultats montrent que les modèles physiologiques réussissent à simuler les variations métaboliques des espèces antarctiques en fonction de l’environnement et à prédire les dynamiques de populations. Cependant, davantage de données sont nécessaires pour pouvoir caractériser finement les différences physiologiques entre populations et évaluer correctement les modèles. Les résultats obtenus pour les SDMs montrent que les modèles générés à l’échelle de l’océan Austral et leurs prédictions futures ne sont pas fiables du fait du manque de données disponibles pour caractériser l’espace occupé par les espèces, du manque de précision des scénarios climatiques futurs et de l’impossibilité d’évaluer les modèles. De plus, les modèles extrapolent sur une très grande proportion de l’espace projeté. L’apport d’information complémentaire sur les limites physiologiques des espèces (observations, résultats d’expériences, sorties de modèles physiologiques) permet de réduire l’extrapolation et d’augmenter la capacité des modèles à décrire la niche réalisée des espèces. L’agrégation spatiale des données, qui influençait les prédictions et l’évaluation des modèles a également pu être corrigée. Enfin, les modèles de dispersion ont montré un potentiel intéressant pour révéler le rôle des barrières géographiques ou à l’inverse, la connectivité spatiale, mais également le lien existant entre distribution, physiologie et histoire phylogénétique des espèces. Ce travail de thèse propose de nombreux conseils et fournit des codes annotés parfois sous forme de tutoriels, afin de constituer une aide utile aux futurs travaux de modélisation sur les espèces marines antarctiques. |
| Programme |
688,1044 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
6439 |
| Permanent link to this record |
| |
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| |
| Author |
Nicolas Meyer, Loïc Bollache, Matthias Galipaud, Jérôme Moreau, François-Xavier Dechaume-Moncharmont, Eve Afonso, Anders Angerbjörn, Joël Bêty, Glen Brown, Dorothée Ehrich, Vladimir Gilg, Marie-Andrée Giroux, Jannik Hansen, Richard Lanctot, Johannes Lang, Christopher Latty, Nicolas Lecomte, Laura McKinnon, Lisa Kennedy, Jeroen Reneerkens, Sarah Saalfeld, Brigitte Sabard, Niels M. Schmidt, Benoît Sittler, Paul Smith, Aleksander Sokolov, Vasiliy Sokolov, Natalia Sokolova, Rob van Bemmelen, Øystein Varpe, Olivier Gilg |
| Title |
Behavioural responses of breeding arctic sandpipers to ground-surface temperature and primary productivity |
Type |
Journal |
| Year |
2021 |
Publication |
Science of The Total Environment |
Abbreviated Journal |
|
| Volume |
755 |
Issue |
|
Pages |
142485 |
| Keywords |
Environmental conditions Incubation behaviour Incubation recesses Incubation strategy Lag effects NDVI Shorebird |
| Abstract |
Most birds incubate their eggs, which requires time and energy at the expense of other activities. Birds generally have two incubation strategies: biparental where both mates cooperate in incubating eggs, and uniparental where a single parent incubates. In harsh and unpredictable environments, incubation is challenging due to high energetic demands and variable resource availability. We studied the relationships between the incubation behaviour of sandpipers (genus Calidris) and two environmental variables: temperature and a proxy of primary productivity (i.e. NDVI). We investigated how these relationships vary between incubation strategies and across species among strategies. We also studied how the relationship between current temperature and incubation behaviour varies with previous day's temperature. We monitored the incubation behaviour of nine sandpiper species using thermologgers at 15 arctic sites between 2016 and 2019. We also used thermologgers to record the ground surface temperature at conspecific nest sites and extracted NDVI values from a remote sensing product. We found no relationship between either environmental variables and biparental incubation behaviour. Conversely, as ground-surface temperature increased, uniparental species decreased total duration of recesses (TDR) and mean duration of recesses (MDR), but increased number of recesses (NR). Moreover, small species showed stronger relationships with ground-surface temperature than large species. When all uniparental species were combined, an increase in NDVI was correlated with higher mean duration, total duration and number of recesses, but relationships varied widely across species. Finally, some uniparental species showed a lag effect with a higher nest attentiveness after a warm day while more recesses occurred after a cold day than was predicted based on current temperatures. We demonstrate the complex interplay between shorebird incubation strategies, incubation behaviour, and environmental conditions. Understanding how species respond to changes in their environment during incubation helps predict their future reproductive success. |
| Programme |
1036 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0048-9697 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7553 |
| Permanent link to this record |
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| Author |
Manon Clairbaux, William W. L. Cheung, Paul Mathewson, Warren Porter, Nicolas Courbin, Jérôme Fort, Hallvard Strøm, Børge Moe, Per Fauchald, Sebastien Descamps, Hálfdán Helgason, Vegard S. Bråthen, Benjamin Merkel, Tycho Anker-Nilssen, Ingar S. Bringsvor, Olivier Chastel, Signe Christensen-Dalsgaard, Jóhannis Danielsen, Francis Daunt, Nina Dehnhard, Kjell-Einar Erikstad, Alexeï Ezhov, Maria Gavrilo, Yuri Krasnov, Magdalene Langset, Svein-Håkon Lorentsen, Mark Newell, Bergur Olsen, Tone Kirstin Reiertsen, Geir Systad, Þorkell L. Þórarinsson, Mark Baran, Tony Diamond, Annette L. Fayet, Michelle G. Fitzsimmons, Morten Frederiksen, Grant H. Gilchrist, Tim Guilford, Nicholas P. Huffeldt, Mark Jessopp, Kasper L. Johansen, Amy L. Kouwenberg, Jannie F. Linnebjerg, Laura McFarlane Tranquilla, Mark Mallory, Flemming R. Merkel, William Montevecchi, Anders Mosbech, Aevar Petersen, David Grémillet |
| Title |
Meeting Paris agreement objectives will temper seabird winter distribution shifts in the North Atlantic Ocean |
Type |
Journal |
| Year |
2021 |
Publication |
Global Change Biology |
Abbreviated Journal |
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| Volume |
27 |
Issue |
7 |
Pages |
1457-1469 |
| Keywords |
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| Abstract |
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| Programme |
330, 388 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1365-2486 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7987 |
| Permanent link to this record |
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| |
| Author |
É Vignon, M.-L. Roussel, I. V. Gorodetskaya, C. Genthon, A. Berne |
| Title |
Present and Future of Rainfall in Antarctica |
Type |
Journal |
| Year |
2021 |
Publication |
Geophysical Research Letters |
Abbreviated Journal |
|
| Volume |
48 |
Issue |
8 |
Pages |
e2020GL092281 |
| Keywords |
|
| Abstract |
While most precipitation in Antarctica falls as snow, little is known about liquid precipitation, although it can have ecological and climatic impacts. This study combines meteorological reports at 10 stations with the ERA5 reanalysis to provide a climatological characterization of rainfall occurrence over Antarctica. Along the East Antarctic coast, liquid precipitation occurs 22 days per year at most and coincides with maritime intrusions and blocking anticyclones. Over the north-western Antarctic Peninsula, rainfall occurs more than 50 days per year on average and the recent summer cooling was accompanied by a decrease of −35 annual rainy days per decade between 1998 and 2015 at Faraday-Vernadsky. Projections from seven latest-generation climate models reveal that Antarctic coasts will experience a warming and more frequent and intense rainfall by the end of the century. Rainfall is expected to impact new regions of the continent, increasing their vulnerability to melting by the preconditioning of surface snow. |
| Programme |
1013,1143 |
| Campaign |
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| Address |
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| Corporate Author |
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Thesis |
Bachelor's thesis |
| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1944-8007 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7935 |
| Permanent link to this record |
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| |
| Author |
Van Hanja J |
| Title |
Caractérisation des habitats marins benthiques en zones côtières aux Iles Kerguelen par analyse d'images sous-marines |
Type |
Master 1 |
| Year |
2021 |
Publication |
Master 1 Océanographie, Université de Liège |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
10 pp |
| Keywords |
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| Abstract |
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| Programme |
1044 |
| Campaign |
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| Address |
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Series Title |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8062 |
| Permanent link to this record |
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| Author |
Meudec L. |
| Title |
Analyse de la diversité des astéries du Plateau des Kerguelen par approches génétique et morphologique et modélisation des habitats |
Type |
Master 2 |
| Year |
2021 |
Publication |
Master 2 Sciences de la Mer, Sorbonne Universités |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
50 pp |
| Keywords |
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| Abstract |
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| Programme |
1044 |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
8063 |
| Permanent link to this record |
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| Author |
Morgan Godard |
| Title |
Caractérisation du comportement alimentaire de l'éléphant de mer Mirounga leonina et liens avec les structures physiques sub-mésoéchelles (1-10km) dans l'océan Austral : une approche par analyse de données fonctionnelles |
Type |
Thesis |
| Year |
2021 |
Publication |
Thèse de doctorat en Océanographie |
Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
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| Keywords |
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| Abstract |
De nombreuses questions restent en suspens quant aux relations existantes entre les processus biologiques et physiques dans l'océan Austral. Pour répondre à ces questions, des enregistreurs électroniques sont déployés sur des prédateurs marins, et notamment sur des éléphants de mer austraux. Ces enregistreurs échantillonnent une grande variété de données physiques, biologies ou comportementales à haute fréquence générant ainsi une quantité considérable d’information. L’ensemble de ces données sont dites fonctionnelles car elles présentent un caractère commun : elles évoluent selon un continuum, qu’il soit spatial ou temporel. L’objectif de cette thèse est donc double, il s’agit d’étudier l’activité alimentaire de femelles éléphant de mer en relation avec les processus physiques de l’océan austral, tout en intégrant le caractère fonctionnel des données échantillonnées. Les résultats obtenus montrent que (1) par rapport aux méthodes classiquement employées, les méthodes d’analyse de données fonctionnelles permettent d’identifier une plus grande variété de comportements de plongées au sens biologique défini. (2) Ces approches fonctionnelles sont plus adaptées pour des données aux fréquences d’échantillonnage variable. (3) L’analyse de données fonctionnelles nous permet également d’accéder à la densité de nos individus, reflet de leur condition corporelle, et les comportements de plongées qu’ils adoptent ont une influence réelle sur cette condition corporelle, à différentes échelles de temps. (4) Il existe une relation entre les caractéristiques des masses d’eau rencontrées par les femelles éléphants de mer et les plongées qu’elles effectuent. |
| Programme |
1201 |
| Campaign |
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Edition |
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ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7727 |
| Permanent link to this record |
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| Author |
Karl-Ludwig Klein |
| Title |
Radio Astronomical Tools for the Study of Solar Energetic Particles II.Time-Extended Acceleration at Subrelativistic and Relativistic Energies |
Type |
Journal |
| Year |
2021 |
Publication |
Frontiers in Astronomy and Space Sciences |
Abbreviated Journal |
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| Volume |
7 |
Issue |
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Pages |
93 |
| Keywords |
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| Abstract |
Solar energetic particle (SEP) events are commonly separated in two categories: numerous “impulsive” events of relatively short duration, and a few “gradual” events, where SEP-intensities may stay enhanced over several days at energies up to several tens of MeV. In some gradual events the SEP spectrum extends to relativistic energies (>1 GeV), over shorter durations. The two categories are strongly related to an idea developed in the 1960s based on radio observations: Type III bursts, which were addressed in a companion chapter, outline impulsive acceleration of electrons to subrelativistic energies, while the large and the relativistic SEP events were ascribed to a second acceleration process. At radio wavelengths, typical counterparts were bursts emitted by electrons accelerated at coronal shock waves (type II bursts) and by electron populations in large-scale closed coronal structures (type IV bursts). Both burst types are related to coronal mass ejections (CMEs). Type II bursts from metric to kilometric wavelengths tend to accompany large SEP events, which is widely considered as a confirmation that CME-driven shocks accelerate the SEPs. But type II bursts, especially those related to SEP events, are most often accompanied by type IV bursts, where the electrons are rather accelerated in the wake of the CME. Individual event studies suggest that although the CME shock is the most plausible accelerator of SEPs up to some yet unknown limiting energy, the relativistic SEP events show time structure that rather points to coronal acceleration related to type IV bursts. This chapter addresses the question what type II bursts tell us about coronal shock waves and how type II and type IV radio bursts are related with relativistic proton signatures as seen by particle detectors on the Earth and by their gamma-ray emission in the solar atmosphere, focusing on two relativistic SEP events, on 2005 Jan 20 and 2017 Sep 10. The importance of radio emissions as a complement to the upcoming SEP observations from close to the Sun is underlined. |
| Programme |
227 |
| Campaign |
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Place of Publication |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
2296-987X |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
7777 |
| Permanent link to this record |
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| Author |
Morten Frederiksen, Olivier Gilg, Glenn Yannic |
| Title |
Cross-icecap spring migration confirmed in a high-Arctic seabird, the Ivory Gull Pagophila eburnea |
Type |
Journal |
| Year |
2021 |
Publication |
Ibis |
Abbreviated Journal |
|
| Volume |
163 |
Issue |
2 |
Pages |
706-714 |
| Keywords |
ecological barrier Greenland icecap high-altitude migration |
| Abstract |
Seabirds rarely cross major terrestrial barriers during seasonal migration, possibly because they have a limited ability to build up fat stores. For the first time, we tracked two Ivory Gulls with GPS loggers during spring migration from the wintering area in Davis Strait to the breeding colony in north-east Greenland. While one bird migrated in March around the southern tip of Greenland, the other delayed migration until May and crossed the Greenland icecap north of 70°N, covering 1345 km in 29 h. Several aspects of the crossing were noteworthy: the track was remarkably direct, the bird made several stops (totalling 6 h) on the icecap, and the bird increased its flying altitude to nearly 3000 m over West Greenland and > 4000 m over East Greenland. |
| Programme |
1210 |
| Campaign |
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| Address |
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Place of Publication |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0019-1019 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
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Approved |
yes |
| Call Number |
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Serial |
6348 |
| Permanent link to this record |
